21485065897 has 2 divisors, whose sum is σ = 21485065898. Its totient is φ = 21485065896.

The previous prime is 21485065873. The next prime is 21485065937. The reversal of 21485065897 is 79856058412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18303654681 + 3181411216 = 135291^2 + 56404^2 .

It is a cyclic number.

It is not a de Polignac number, because 21485065897 - 2¹⁹ = 21484541609 is a prime.

It is not a weakly prime, because it can be changed into another prime (21485065807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10742532948 + 10742532949.

It is an arithmetic number, because the mean of its divisors is an integer number (10742532949).

Almost surely, 2^21485065897 is an apocalyptic number.

It is an amenable number.

21485065897 is a deficient number, since it is larger than the sum of its proper divisors (1).

21485065897 is an equidigital number, since it uses as much as digits as its factorization.

21485065897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4838400, while the sum is 55.

The spelling of 21485065897 in words is "twenty-one billion, four hundred eighty-five million, sixty-five thousand, eight hundred ninety-seven".